Increase in oral cancers linked to HPV

The human papillomavirus is contributing to the growing number of head and neck cancers in the United States, according to a new study Monday in the Journal of Clinical Oncology.

The study found that the number of cases of oropharyngeal cancer - cancers of the tonsil, back of the mouth (throat) and base of the tongue - has been on the rise since the mid-1980s. The study suggests that one reason could an increase in the number of people having oral sex resulting in oral human papillomavirus exposure.

Researchers say these cancers fall into two categories–those caused by tobacco and alcohol and those caused by the sexually transmitted virus, HPV. They now believe approximately 70% of all oropharyngeal cancers are caused by HPV infection.

"We used to think of oropharyngeal cancer as one cancer," said senior author Dr. Maura Gillison, The Ohio State University Comprehensive Cancer Center in Columbus. "Now we know the disease is comprised of two biologically and epidemiologically distinct cancers. This new understanding will increasingly enable us to improve and better personalize care for patients with each form of the disease."

Researchers tested cancer tissue samples from almost 6,000 patients in Hawaii, Iowa and Los Angeles between 1984 and 2004. They found the HPV-positive cancers increased 225% while HPV-negative oropharynx cancers dropped 50%–most likely because of a reduction in smoking and tobacco use. Even so, patients with HPV-positive cancers live longer.